Spinal fusion is sometimes necessary for patients having lumbar degenerative disc disease. It has been estimated that at least thirty percent of people aged thirty to fifty will have some degree of disc space degeneration, although not all will have pain or ever be diagnosed formally with degenerative disc disease. After a patient reaches sixty, it is more normal than not to have some level of disc degeneration.
A twisting injury often starts degenerative disc diseases, but it can also be initiated by every day wear and tear on the spine. Lower back pain is the most common symptom of a compromised disc emblematic of degenerative disc diseases. For most patients with lumbar degenerative disc disease, the pain is for the most part tolerable and low-grade, but continuous with occasional flaring of intense pain.
Pain can be simply centered on the lower back, or it can radiate to the hips and legs. It can get worse by sitting, or it can be intensified by twisting, lifting, or bending. For some, the pain from the disease decreases over time, since a fully degenerated disc has no pain-causing inflammatory proteins, and the disc usually collapses into a stable position-eliminating the micro-motion that often generates the pain.
Stabilization of vertebrae relative to each other, by implanting inter-body fusion devices, is a well-accepted surgical technique and has increasingly been used to correct for degenerative disc disease. The implantation of internal fusion devices can often be traumatic. If insufficient stabilization or incorrect anatomical alignment occurs, then revision surgery or on-going pain may be experienced by the patient.
Many variations of this basic surgical technique exist but often require considerable time and effort for successful implant placement. This is frequently due to the fact that such systems typically require both excessive surgical tissue dissection and mechanical vertebral distraction such that the various stabilization components of the system can be successfully positioned in a patient's intervertebral space.
In addition, dimensional constraints typically imposed by access considerations are often in conflict with the desire to place the largest implant possible having an effective anatomical shape to support the loads transmitted across the vertebral endplates. Specifically, the larger and more curved the implant inserted, the greater the amount of resulting tissue damage both in the intervertebral space, and in the surrounding tissues. There is therefore a need for devices for introduction into a body in a substantially straight configuration and to form a predefined curved configuration, to reduce time, to reduce effort, and to reduce tissue damage.
Solutions have been long sought but prior developments have not taught or suggested any complete solutions, and solutions to these problems have long eluded those skilled in the art. Thus a considerable need still remains.